With the miniaturization of a semiconductor integrated circuit, there has been demanded the miniaturization of an active region, an element isolation insulating film, and a gate electrode, which are formed in a semiconductor substrate. The element isolation insulating film is formed by embedding an oxide film in a groove formed in the semiconductor substrate. The element isolation insulating film is formed in the semiconductor substrate, whereby the active regions are partitioned.
[Patent document 1] Japanese Laid-open Patent Publication No. 2009-252825
[Patent document 2] Japanese Laid-open Patent Publication No. 2009-176407